Improvement in steam fog-alarms



W. E. LEIGHTON. Steam Fog-Alarm.

No. 218,286. Patented Aug. 5,1879.

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UNITED STATES PATENT QFFIGE.

WILLIAM E. LEIGHTON, OF WEST PEMBROKE, MAINE.

IMPROVEMENT IN STEAM FOG-ALARMS.

Specification forming part of Letters Patent No. 218,286, dated August5, 1879; application filed July 14, 1879.

To all whom it may concern:

Be it known that 1, WILLIAM E. LEIGHTON, of West Pembroke, in the countyof Washington and State of Maine, have invented a new and usefulImprovement in Steam Fog- Alarms, of which the following is aspecification.

Figure l is a vertical longitudinal section of my improved apparatus,taken through the line x 00, Fig. 2. Fig. 2 is a top view of the same,partly in horizontal section, through the line yy, Fig. 1. Fig. 3 is adetail side view of the whistle. Fig. at is a detail view of theperforated base-plate. Figs. 5, 6, and 7 show different forms for thesteam-escape orifices of the whistle.

Similar letters of reference indicate correspondin g parts.

The object of this invention is to furnish an improved apparatus forgiving fog-signals with steam-whistles, which shall be so constructed asto increase the intensity of the sound and project it farther than hasheretofore been practicable.

A represents the fog horn, which is made of any desired length and size,and with a flaring or bell-shaped mouth.

Upon the upper side of the rear part of the horn A is formed a closedchamber, B, to receive the upper part of the steam-whistle.

Upon the lower side of the horn A, directly beneath the chamber B, isformed a chamber, 0, to receive the lower part of the steamwhistle. Thechamber 0 is closed by a baseplate, D, which has a number of holesformed through it to admit air to fill the vacuum formed in the lowerpart of the horn by the rapid entrance of the steam. In the center ofthe base-plate D is formed a hole, in which is secured the pipe E,through which the steam is introduced.

To the end of the steam-pipe, E or to the base-plate D, around the saidend, is attached the base of the lower part, F, of the steamwhistle, tothe top of which is attached the standard G, that supports the bell H.The bell H is secured to the upper end of the standard G by a nut, g.

The lower part, F, of the whistle is made with closed ends and with twostraight parallel orifices, f, for the escape of the steam; and the bellH is made with closed ends and with two straight parallel edges, h, toreceive the steam as it issues from the said oriflees f and give thesound.

The whistle F G H is arranged within the fog-horn A. with the orifices fand edges h at right angles with the length of the said horn.

The whistle may be made with two straight parallel orifices, f, as shownin Figs. 1, 2, and 7, or with one straight orifice, as shown in Fig. 6,or with one curved orifice, as shown in Fig. 5; but I prefer theconstruction first described, as giving better results.

In the rear part of the horn A is placed a plate, I, to receive theWaves of sound and reflect them out through the mouth of the said horn.The reflector I is swiveled to the end of the screw J, which passes inthrough a screw-hole in the rear end of the horn A, and has a lever orother handle attached to its outer end, so that the reflector I can bereadily adjusted nearer to or farther from the whistle F G H, ascircumstances may require.

The reflector I is made adjustable, in order that the column of air backof the whistle may be shortened or lengthened until its vibrationssynchronize with those of the whistle. On account of interference, therewill be no augmentation of sound unless this correspondence in theresonance of the air takes place.

The object of constructing the whistle with the straight orifices f fand the straight parallel sides h is to give a greater volume of soundin any particular direction, instead of expending the force in alldirections, as is the case with a whistle having an annular orifice.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The fog-horn A, provided with opposite chambers BO, at right angles thereto, a perforated plate, D, and asteam-whistle,arranged as shown and described.

2. The lower part, F, of whistle, provided with one or more straightorifices, f f, and the bell H, with one or more straight sides, It, asand for the purpose set forth. a

3. The reflector I, arranged in a fog-horn in the rear of asteam-whistle, and made adjustable with respect thereto, as and for thepurpose specified.

WILLIAM E. LEIGHTON.

Witnesses BELA A. WILDER, N. 0. BROWN.

